Engine starting mechanism



April 1942- R. M. NARDONE 2,279,126

ENGINE STARTING MECHANISM Filed Sept. 26, 1959 2 Sheets-Sheet l INVENTOR.

1 omeo M Nardbne ifi g d RM. NARDONE .ENGINE STARTING MECHANISM [I ll l.llllll ll l.

Filed Sept. 26, 1939 April 7, 1942.

INVENTOR.

Romeo M-A/ardone nnnrmi Patented n, 1942" Enema sraa'rmc MECHANISM Romeo M. Nardone, East Orange, N. 1., assignor to Bendix Aviation Corporation, South Bend,

1nd,, a corporation of Delaware v Application September 26, 1929, Serial No. 296,681 15 Claims. (01. 123-179) This invention relates to engine starting mechanism and more particularly to a starting mechanism of the inertia type, in which ,there is a period of energy storage in an inertia. element (flywheel, for example) prior to movement of the engine engaging, or cranking element, to cranking engagement with the member of the engine to which initial rotary movement is to be imparted.

preciable amount of energy accumulated in the flywheel is lostfirst, through the slippage of an overload release clutch and secondly, by the fact that some energy remains unused at the moment when the engine starts; and even on the oc casions when the cranking eifort is continued until the flywheel energy is used, the energy remaining at speeds below 4000 R. P. M. is ineileetive, due to the low engine cranking speed from that point down to zero. In other words, on such occasions, there is a failure of the engine to start. Further, inertia starters engage at maximum rotary speed, thereby imposing a torque value on the engine member which is normally above the slipping value of the overload release clutch. This tends to create a condition of shock, at first engagement.

Objects of the present invention are to make advantageous use of all the energy of the flywheel all the way down to zero flywheel speed; and to minimize the shock of engagement. I propose to bring about by engaging the starter and engine jaws at zero rotary'speed, thereafter increasing the rotative speed of the starter jaw.

Another object is to crank the engine at speeds over and above that which would normally obtain with a fixed gear ratio between flywheel and engine engaging jaw. the cranking speed being characterized by a tendency to increase during at least the initial stage of the run-down period of the flywheel, rather than to decelerate therewith, as has been the tendency heretofore.

Still another object is to produce a direct cranking action by use of energy from a prime mover additional to the flywheel, said prime mover being operative, first, to accelerate the flywheel, and subsequently-upon reversal in its direction of rotationbeing instrumental in establishing connection between the starter and en- 4 glue, and also in helping the flywheel to speed up the engineand continue to transfer energy thereto even after the flywheel has come to a complete stop. and so long as is necessary to insure eflective starting.

The latter These and other objects of. the invention will become apparent from inspection of the following specification when read with reference to the accompanying drawings wherein is illustrated the preferred embodiment of the invention. It is to be expressly understood, however, that the drawings are for the purpose of illustration only, and are not designed as a definition of the limits 01' the invention, reference being had to the appended claims forthis purpose.

In the drawings:

Fig. l is a central sectional view of a device embodying the invention;

Fig. 2 is a view partly in section and partly in elevation of a modified embodiment of the starter shown in Fig. 1; and w a Fig. 3 is a diagram of electrical parts and connections applicable to control energization of the 6 is provided with a second flange 1 to receive bolts 8 for securing the starter to the crankcase of an engine, a portion of the latter being indicated at 9. Secured to one side (top, as shown) of section 3 is an electric motor Ill provided with a casing H having a flange to register with a corresponding flange on casing section 3, and be supported thereby.

The motor may be of any suitable type embodying an armature shaft l3 provided with a projecting, reduced portion I! that is rotatably mounted as by means of a suitable bearing IS in the flywheel 22, also the Shaft 23 to which said hub 2| is keyed as indicated. Said shaft 23 also has keyed thereto a ratchet toothed clutch element 2t, and at its opposite end the shaft is formed into a pinion, as at 28, constituting the "sun," or central element of a planetary system whose several planet pinions, as at 21 and 28. mesh with the orbital gear l8 heretofore referred to. A second ratchet element 3| is splined upon stationary sleeve 32 embedded in rear cover plate tion a spring 36 which yieldably urges the ratchet element 3| into mesh with ratchet element 24, thereby restricting flywheel 22 'to rotation in a .single direction only.

A second planetary system includes a planet carrier 38 inetgral with a sun gear 39, and is rotatably mounted as by means of a bearing 4| on a stub shaft 42 that extends outwardly from, and is drlvably connectedto, a barrel 43 having a closed end 44, the stub shaft being integral withsaid closed end in the illustrated embodiment of the invention. Ball bearings 33, carried by the inner housing section 4 are preferably employed for rotatably mounting the barrel 43.

'Gear 33 meshes with a plurality of planetary gears 4| that are rotatably mounted on the barrel end 44 and mesh with an annulus gear 41 which isflxedly mountedwithin the houslngby means of studs 43. Preferably three planetary gears 46 are-employed, and one of these is 'shown,

insectloninllgl. Thesegearsflarepref- 33, and a smaller cover plate 34 holds in posia shoulder formed 'interiorly of nut ll. Preferably a coil spring 18 is interposed between jaw clutch member 64 and shaft 14, a portion of said spring extending into a recess formed in the inner end of the shaft, to yieldingly resist relative movement of the parts.

The starter is preferably provided with the usual oil sealing means for preventing oil in the engine crankcase 8 from seeping into the starter housing. This includes a cup-shaped member 3! that is preferably formed of metal and is proyided with a flange 32 on the outer end thereof,

- bent inwardly toward jaw member 34, and is provided with a central opening which is slightly In order to prevent seepage of oil through the central opening in member II, the latter preferably carries the usual washer of leather or erably spaced 120.apart, so that as the istakeninl'lg.i,oneofthegearsappearsin' elevatloniust below the stub shaft 43. Each of the planetary gears (and the same is trueof planets 21, 23) is rotatably mounted by means of a ball bearing, atjll carried by a sleeve. whichiscountersunkatitsinnerendinbarrel thelikesecuredinany suitable mannerto the shoulder provided adjacent the bend of member 3|. Normally the innerportion ofthe washer is held in engagement with the adjacent surface of the head of jaw member 34 by means of a sleeve end 44. 'IA screw 2 supports each sleeve, bearingand planetary gear. .If desired, a retaining ring [3 for the bearings I may be provided, as

. an integral part of the screw receiving sleevu.

As shown, annulus 41 has two orbital tracks,

the second being engaged, by planet pinions I3 rotatably mounted (by parts similar to those supporting pinions II) to turn with carrier 33 above described, and each meshing with a sun gear 31 formed on one end of a shaft I3 con-. necting said gear with the carrier 83 of the planets 21, II. A second ratchet clutch has one element ii integrated with planet carrier 33,

the adiacent'element 32 being splined tests- 1 tionary boss 33 of wall 84. Springs I urge clutchpart 32 into engag ment with part 3|, to restrict rotation of planet carrier 33 to a single di e on. V Th electricmotor .II is adapted to drive an seal member ll.

which slidably surrounds the cylindrical portion 344 of the jaw clutch member and abuts at its outer end against a flange provided on nut Il..

The outer periphery of the head of. member II .is provided with longitudinally disposed slots ce'ntralopening inmember 3|: thisconstruction being more fully illustrated in Patent No. 1,962,-

39'? granted to Raymond P. Lansing on June 12,

There is also preferably provided the usual 'rodltwhichslidablyextendsthroughstubshaft engine engaging member 34 through the train.

- of reduction gearing described above. The

member I4 constitutes one element of a jaw clutch, "the other element being formed by a r member I, carried by a rotating art of the engine to be cranked, such as the engine crank Y shaft or an extension thereof.. There is also pref- .erably employed the usual multiple disk clutch embodying a plurality of frictiondisks i3,-a number of said disks being splined to the inner surface of barrel 43, and the remainder being splined to the outer surface of an interiorly threaded nut 1i. Resilient means such as a plurality of coil springs I2 and an adjusting nut 13, which is threaded into the inner end of barrel 43, are

provided for varying the pressure with which disks 9' are maintained in engagement.

Mounted for rotary and longitudinal movement within nut II is the usual threaded shaft I4 which is longitudinally splined at its inner" end to drivably engage a correspondingly splined,

tubularand outwardly extending portion 84 of lifbarrel end, threaded shaft 14 and a cen-' opening in the hub of member 3|. The inner portionofrodilisofreduceddia'meter to provide a shoulder 03 which normally abuts againsttheouter endofshaft l4. Theinner end of rod is threaded to receive-a nut which abuts the hub of jaw member 34 and coacts with shoulder 3| to retain said member and shaft in operative relationship.

During flywheel acceleration, all planetary spiders are stationary and therefore the starter barrel 43 does not rotate. After proper flywheel speed is obtained, the direction of motor rotation is reversed by any suitable circuit arrangement (as in' Fig.3 hereinafter described), as by cutting, oi! the current in one set of fleld coils and sending it through a second set of fleld coils. when this-circuit change is made, the motor rapidly decelerates to zero, under the action of the reverse current, and the speed of gear l3 in the jaw clutch member 34. -'Movement of thread ed shaft 14 tothe left, as viewed in'Flg. 1, relative to nut-ll is positively limited by means of a member I! threaded on the outer end of shaft l4 and constituting a stopfor engagement with its original direction of rotation is thereby decreased. This decrease lin speed of gear 13 causes all planets to rotate, which rotation is of course communicated tothe starter barrel 43.

' This results in immediate screw action at ll, 14,

whereupon starter jaw 84 starts-to move forward, into engagement with the enginejaw. Engage I away torque of the engine.

ment is therefore at zero speed and zero torque; hence there is no slippage at clutch 89. However, during this deceleration of the motor to zero speed some flywheel energy 'is lost, due to the drag of the decelerating gear l8 upon the flywheel; but this loss is slight as compared with what is saved by reason of the absence of any As the flywheel comes to zero speed, clutch 3|,

26 takes hold and prevents its rotation in the reverse direction. Gear I8 continues to be rotated by the motor and the engine is cranked at a speed corresponding to motor speed divided by the ratio between it and the jaw =64. Direct cranking (from motor H] to jaw 64) may thus continue until the engine starts, Maximum torque at the jaw 54 is a function of the maximum torque of the motor during its reversal, and the gear ratio between motor and jaw. This torque must in all cases be appreciably higher than the break- Were it not so, the engine would not move, and all the energy in the flywheel 'would be expanded in rotating the motor armature against its electrical torque.

In some installations it may be preferred to employ an added element to facilitate the action v of reversing the direction of motor rotation after acceleration of the flywheel. Such an element may take the formof a brake engageable with a suitable surface on the armature shaft or other rotating part of the motor; and as illustrated in Fig. 2 such a brakemay consist of a pair of cone clutch elements IOI and I02 normally held engaged by springs I03; said springs being yieldable to permit movement of the outer element I02 to the disengaged position upon passage of current through a winding I04 of an electromagnet whose plunger type armature is thereby shifted to produce such disengaging movement of the element I02, through the action of a yoke Hi5, p'ivotally' mounted at 52d, and mechanically linked to the magnet plunger I01 as shown in Fi 2.

Winding 184 is shown as being in circuit with a source 905 and a switch M8 (Fig. 3) when the latter occupies a position of engagement with either contact ill or contact H2, these being the contacts controlling shunt field coils H3 and ill,

of rotation of the motor illgwhose armature winding is indicated at H5 in Figs. 2 and 3. Thus it will be apparent that the brake will be inefiective so long as current is flowing to the motor windings, but will immediately become effective as the switch it is moved away from contact H I and toward contact H2, preparatory to reversal of the direction of rotation.

What I claim is:

- 1. In an engine starter, the combination of a rotating inertia member, means for driving the inertia member including a driving gear. a driven gear and an intermediate reactance gear, said reactance gear being rotatably mounted in a rotatable frame, means for connecting said rotatable frame to the engine in a mannerto crank respectively, and hence controlling the direction the same, means acting upon, and through the agency of, said connecting means for preventing rotation of the frame in one directiom'and means acting upon said driving gear for reducing the speed of the'driving gear whereby the reaction force on the frame is reversed and the frame is rotated in a direction to crank the engine.

1 2. In an engine starter, the combination of a rotating inertia member, means for driving the inertia member including a driving gear, a driven gear and an' intermediate reactance-gear, said reactance gear being rotatably mounted in a rotatable frame, means for connecting said rotatable frame to the engine in a manner to crank the same, means acting upon, and through the agency of, said connectingmeans for preventing rotation of the frame in one direction, and means acting upon said driving gear for first decelerating and thereafter reversing the direction of rotation of the driving gear whereby the reaction force on the frame is reversed and the frame is rotated in a direction to crank the engine.

3. Invan engine starter, the combination of a rotating inertia member, means for driving the inertia member including a driving gear, a driven gear and an intermediate reactance gear, said reactance gear being rotatably mounted in a rotatable frame, means for connecting said rotatable frame to the engine in a manner to crank the same, means acting upon, and through the agency of, said connecting means for preventing rotation of the frame in one direction, means acting upon said driving gear for first decelerating and thereafter reversing the direction of rotation of the driving gear whereby the reaction force on the frame is reversed and the frame is rotated in a direction to crank the engine, said last-named means also acting to concurrently decelerate the inertia member and thereafter tending to reverse the direction of rotation thereof, and means distinct from, and acting separately from, said last-named means to prevent such reverse rotation of the inertia member.

4. In an engine starter, the combination of an inertia member, means for rotating the inertia member including a gear train having one element thereof drivably connected to said inertia member, a rotatable frame supporting a second element of said gear train, means for connecting said rotatable frame to the engine to be started for transmission of initial rotary movement to the latter, and means acting upon, and through the agency of, said connecting means for holding said frame stationary during the rotation of the inertia member for storage of energy therein.

5. In combination with an engine-engaging member and a flywheel, accelerating means therefor comprising a reversible motor and a source of current for energizing said motor, means for holding said engine-engaging member at zero speed during operation of said energizing means to rotate said motor in the flywheel accelerating direction, means for reversing the current flow from said source to said motor, toreverse the direction of motor rotation, and means responsive to operation of said reversing means to move said engine engaging member to engineengaging position.

6. In combination with an engine-engaging member and a flywheel, accelerating means therefor comprising a reversible motor, means for rotating said motor in the flywheel accelerating direction independently of any rotation of said engine-engaging member, means for reversing the direction of motor rotation and means responsive to operation of said reversing means to transfer to said engine, through the agency of said engine-engaging member. the energy previously stored in said flywheel.

7. In combination with an engine-engaging member and a flywheel, accelerating means therefor comprising a reversible motor, a current source and a switch which, in one position, di-' ber by said accelerating means, means to reverse the directionof rotation of said motor, and means a responsive to operation of said reversing means rects current to said motor for rotation thereof in the flywheel accelerating direction, and when in another position causes current flow for rotation of said motor in the reverse direction-and means responsive torotation of said engine-engaging member to transfer to said engine-engaging member the energy previously stored in saidflywheel during operation of said motor in the flywheel accelerating direction, said lastnamed means further operating to continue cranking the. engine through the agency of said engine-engaging member even after deceleration of the flywheel to zero speed;

8. The method of operating an engine starter of the type having an engine-engaging member, a prime mover and an inertia member energizabie in response to operation of said prime mover,

D to cause rotation of'said frame and engine-engaging member in a direction to transfer to the engine,- through the agency of said frame and engine-engaging member, the energy stored in said inertia member during acceleration thereof.

12; In an engine starter, the combination with a rotating inertia member and an engine-engaging member, of means including a reversible motor for accelerating the inertia member, means for preventing rotation of said engine-enga ing member during acceleration 'of the inertia member by said accelerating means, means to reverse which includes the steps of first energizing the prime mover to produce energy storage in the inertia member. then coupling the engine-engag- 4 ing member to the engine at zero rotary speed for transfer to the latter of the energy stored in the inertia member. and thereafter causing the delivery of energy from the prime mover to the engine-engaging member independently of the inertia member.

9. In an engine starter, the combination of a rotating inertia member, means for driving the inertia member including a reversible motor, a driven gear and an intermediate-reactance gear, said reactance gear being rotatably mounted in a rotatable frame, means responsive to rotation of said rotatable frame forconnecting said rotatable frame to the engine in a manner to crank the same, and means responsive to reversal in the direction of rotation of said reversible motor for reducing the speed of-the driving gear whereby the reaction force on the frame is reversed and the frame is rotated in a direction to crank the engine.

10. In an engine starter. the combination of a rotating inertia member, means for driving the inertia member including areversible motor, a

driven gear and an intermediate reactance gear, and reactance gear being rotatably mounted in a rotatable frame, means responsive to rotation of said rotatable frame for connecting said roreverse rotation of the inertia member.

11. In an engine starter, the combination with a rotating inertia member and an engine-engagresponsive to operation of said reversing meansv for causing rotation of-said engine-engaging member in a direction to transfer to the engine, through the agency of said engine-engaging member, the energy stored in said inertia member during acceleration thereof.

13. In combination with an engine-engaging member and an inertia element, means including areversible motor for accelerating said inertia element, means to reverse the direction of rotation of said motor, and means responsive to operationof said reversing means for operating upon said accelerating means to cause transfer to said engine-engaging member of the energy stored in said inertia element during initial operation of said accelerating means, said lastnamed means further operating to continue cranking the engine through the agencyof said engine-engaging member even after deceleration of the flywheel to zero speed.

14. In combination with an engine-engaging member and a flywheel, accelerating means therefor comprising a reversible motor and a switch which, in one position, causes operation of said motor in the flywheel accelerating direction, and means responsive to rotation of said motor in the reverse direction to transfer to said engine-engaging member the energy previously stored in said flywheel.

15. In an engine starter, the combination of a reversible electric motor, an engine-engaging member, means drivably connecting said motor to said engine-engaging member including a rotatable frame and a gear train having elements thereof supported by said frame and rotatable by said motor, means acting upon, and through the agency of, said connecting means for holding said frame stationary during the rotation of said motorin one direction, means for reversing the direction of rotation of said motor, and means responsive to operation of said reversing means for rendering said holding means ineffective to prevent transmission of torque from said motor ROMEO M. NARDONE. 

